This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We have developed conditions to purify prions for structural analysis, but these preparations still contain lipids that associate with the prion protein. Included in the lipid poos are gangliosides and ceramides, which were initially assigned by thin layer chromatography (TLC);complex mixtures of these classes have now been defined by tandem mass spectrometry. At the Resource, LC/MS/MS is being used to identify the components of the prion-associated lipid pool. This has resulted in the identification of more than one hundred lipids, and has enabled comparisons between the samples. Further samples from animals with different stages of disease are being analyzed.